IIG MinWool LLC 

Phenix City Plant

Startup, Shutdown, Malfunction Plans

MACT

Operations, Maintenance, Monitoring Plans
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

Table of Contents

A Applicability ............................................................................................................... 5

B General Information.................................................................................................... 6

B.1 Recordkeeping .................................................................................................... 6

B.2 Modifications to Plan.......................................................................................... 6

B.3 General Malfunction Procedures ........................................................................ 6

B.4 Resin Free Formaldehyde Content...................................................................... 6

B.5 Cupola................................................................................................................. 7

B.5.1 Description.................................................................................................. 7

B.5.2 MACT – Carbon Monoxide........................................................................ 7

B.5.3 MACT – PM as HAP Surrogate ................................................................. 7

B.5.4 Cupola w/ Baghouse ................................................................................... 8

B.5.4.1 Overview................................................................................................. 8

B.5.4.2 Startup and Shutdown of Cupola ............................................................ 8

B.5.4.3 Malfunctions of Cupolas......................................................................... 8

B.5.5 Baghouses................................................................................................... 9

B.5.5.1 Overview................................................................................................. 9

B.5.5.2 Malfunction............................................................................................. 9

B.5.5.3 Monitoring .............................................................................................. 9

B.5.6 Bag Leak Detection System........................................................................ 9

B.5.6.1 Overview................................................................................................. 9

B.5.6.2 Operations & Maintenance ................................................................... 10

B.5.6.3 Responding to Leak Detector Alarms................................................... 10

B.5.7 Cupola Melt Rate Monitoring................................................................... 10

B.5.7.1 Overview............................................................................................... 10

B.5.7.2 Melt Rate Measurement........................................................................ 11

B.6 Rockwool Curing Oven .................................................................................... 11

B.6.1 Description................................................................................................ 11

B.6.2 MACT – Formaldehyde as HAP Surrogate .............................................. 11

B.6.3 Curing Oven Startup & Shutdown............................................................ 11

B.6.4 Oven Incinerator ....................................................................................... 12

B.6.4.1 Overview............................................................................................... 12

B.6.4.2 Malfunction........................................................................................... 12
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

B.6.4.3 Annual Inspections................................................................................ 12

B.6.5 Oven Incinerator Temperature Monitoring............................................... 12

B.6.5.1 Overview............................................................................................... 12

B.6.5.2 Malfunctions......................................................................................... 12

C Resin Free Formaldehyde Monitoring...................................................................... 13

C.1 Resin Vendor Certificate of Analysis............................................................... 13

C.2 Monitoring ........................................................................................................ 13

C.3 Corrective Actions............................................................................................ 13

C.4 Required Records.............................................................................................. 13

D Cupola and Curing Oven SSM/OMM ...................................................................... 14

D.1 Cupola............................................................................................................... 14

D.1.1 Startup and Shutdown Procedures............................................................ 14

D.1.2 Required Records...................................................................................... 14

D.1.3 Baghouse................................................................................................... 16

D.1.3.1 Operations & Monitoring...................................................................... 16

D.1.3.2 Maintenance: Calibration and Inspections........................................... 16

D.1.3.2.1 Calibration...................................................................................... 16

D.1.3.2.2 Inspections ..................................................................................... 16

D.1.3.2.3 Envirotech System Maintenance.................................................... 18

D.1.3.2.4 Spare Parts List .............................................................................. 18

D.1.3.3 Operational Malfunctions ..................................................................... 18

D.1.3.3.1 Baghouse Inlet High Temperature Alarm...................................... 18

D.1.3.3.2 Other Bypass Events...................................................................... 18

D.1.3.4 Responding to Leak Detector Alarm .................................................... 19

D.1.4 Bag Leak Detection System...................................................................... 20

D.1.4.1 Monitoring ............................................................................................ 20

D.1.4.2 Maintenance & Calibration................................................................... 20

D.1.5 Cupola Melt Rate Monitoring................................................................... 22

D.1.5.1 Operation............................................................................................... 22

D.1.5.2 Monitoring Requirements..................................................................... 22

D.1.5.3 Calibration Program.............................................................................. 22

D.1.5.4 Malfunctions......................................................................................... 23

D.1.6 Spare Parts List ......................................................................................... 23
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

D.2 Curing Oven and Incinerator ............................................................................ 24

D.2.1 Startup and Shutdown Procedures............................................................ 24

D.2.2 Maintenance.............................................................................................. 24

D.2.3 Incinerator................................................................................................. 24

D.2.3.1 Annual Incinerator Inspection............................................................... 24

D.2.3.2 Malfunctions......................................................................................... 25

D.2.3.2.1 Exhaust Fan Malfunction............................................................... 25

D.2.4 Incinerator Temperature Monitoring ........................................................ 25

D.2.4.1 Monitoring Parameter Deviation .......................................................... 25

D.2.4.2 Maintenance and Calibration ................................................................ 25

D.3 Binder Formulation Monitoring........................................................................ 26

D.3.1 Binder Formulation................................................................................... 26

D.3.2 Monitoring ................................................................................................ 27

D.3.3 Monitoring Parameter Deviation .............................................................. 27

E Appendices................................................................................................................ 28

E.1 Regulations ....................................................................................................... 29

E.1.1 General Provisions 40CFR63 Subpart A.................................................. 29

E.1.2 MACT – Mineral Wool Production – 40CFR63 Subpart DDD ............... 29

E.2 Resin Free Formaldehyde ................................................................................. 30

E.2.1 Resin Specification – Dynea 367.10......................................................... 30

E.2.2 Resin Certificate of Analysis.................................................................... 30

E.3 Equipment Documents...................................................................................... 31

E.3.1 Cupola – General Description................................................................... 31

E.3.1.1 Cupola and Envirotech P&ID ............................................................... 35

E.3.2 Curing Oven – General Description ......................................................... 36

E.3.2.1 Curing Oven Diagram........................................................................... 37

E.3.3 Baghouse Leak Detector........................................................................... 38

E.3.3.1 Manufacturer Certification.................................................................... 38

E.3.3.2 USEPA Guidance on Baghouse Leak Detectors .................................. 38

E.4 Incinerator Inspections...................................................................................... 39

E.4.1 Annual Incinerator Inspection SAP Document......................................... 39

E.4.2 Most Recent Report .................................................................................. 39

E.5 Required Checklists.......................................................................................... 40
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

E.5.1 Cupola Startup/Shutdown Checklists ....................................................... 40

E.5.2 Oven Startup/Shutdown Checklist............................................................ 40

E.5.3 Pressure Transmitter Calibration Checklist .............................................. 40

E.5.4 Baghouse Checklists................................................................................. 40

E.5.4.1 Monthly Inspection Checklist............................................................... 40

E.5.4.2 BHA Bi-Annual Inspection Proposal / Checklist ................................. 40

E.5.4.3 Baghouse High Temperature Alarm..................................................... 40

E.5.4.4 Leak Detector Alarm Checklist ............................................................ 40

E.5.4.5 General Baghouse Bypass Checklist .................................................... 41

E.5.5 Cupola Flue Gas Treatment Maintenance Checklists............................... 41

E.5.6 Curing Oven System Maintenance Checklists.......................................... 41

E.5.7 Incinerator Checklists ............................................................................... 41

E.5.7.1 Incinerator Temperature Calibration Procedure ................................... 41

E.5.7.2 Incinerator Exhaust Fan Failure Checklist............................................ 41

E.5.7.3 Incinerator Low Temperature Alarm.................................................... 41

E.5.8 Malfunction Procedures not Listed: Form................................................ 41

E.6 Historic Documents .......................................................................................... 42

E.6.1 Notifications.............................................................................................. 42

E.6.2 Test Protocol ............................................................................................. 42

E.6.3 Final Compliance Report .......................................................................... 42

E.7 Applicable Requirements: Summary ............................................................... 43

E.8 Version Control Section.................................................................................... 44
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

A Applicability

These plans are implemented pursuant to the requirements of 40 CFR 63, Subparts A and 

DDD. Copies of these regulations can be found in the Appendix, Section E.1. As such, 

these plans cover only those aspects of the affected facilities that relate to the control of 

the surrogate species selected by the agency for the covered HAPs, i.e., formaldehyde for 

curing ovens and particulate emissions for the cupola.

Additional activities required for the safe and productive operation of the equipment are 

captured in other, appropriate documents.

This document contains 

 Startup and Shutdown plans for the affected sources, 

 Malfunction plans for the sources and control equipment, and

 Operations, Maintenance, and Monitoring plans for the control equipment and 

monitoring devices.

 A summary of all Applicable Requirements based on Performance Sampling and 

the MACT Regulations. (See Appendix E.7)

The required documents are identified in the table below. 

Required Procedures

Area Type

Startup/ ShutdownMalfunctionMonitoring & Corrective ActionsOperations & Maintenance

Resin Free 

Formaldehyde Monitoring X

Cupola Source X

Baghouse Control 

X

Corrective 

actions for 

leak alarm.

X

Baghouse Leak 

Detector

Monitoring X X

Cupola Melt Rate Monitoring X X

Manufacturing Line Source X

Oven Incinerator Control X Annual Inspection

Incinerator Temp Monitoring 3-hour block X

Binder formulation Monitoring Formulation 

of each batch
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

B General Information

B.1 Recordkeeping

Records required by the MACT standard must be retained for five (5) years. The most 

recent two (2) years of records must be kept on site. Required records are listed in each 

section. 

B.2 Modifications to Plan

Per the requirements of §63.1186, the limits established through the initial performance 

tests may be changed if additional performance tests are completed to support those 

changes. Proper notifications and agency involvement is required. 

B.3 General Malfunction Procedures

MACT Requirements:

There are regulatory requirements to follow the procedures outlined below for 

malfunctions occurring that impair the operation of the ESP. When a malfunction occurs 

that impacts the operation of the unit, follow the attached checksheets to insure 

malfunction plans are followed. Checksheets can be found in the Appendix, Section E.2.

MALFUNCTIONS LISTED IN PLAN

In cases where a malfunction occurs that is not part of the list included in the Appendix, 

special instructions must be followed and documented. A responsible individual must:

MALFUNCTIONS NOT LISTED IN PLAN

 Record date and time of malfunction.

 Record nature of malfunction and steps taken to correct.

 Record date and time when malfunction is corrected.

 Develop a new checksheet and incorporate into this plan.

 Contact appropriate agency personnel.

A copy of a checklist suitable for documenting information in these cases can be found in 

the Appendix, Section E.5.8.

B.4 Resin Free Formaldehyde Content

The free formaldehyde content of the incoming resin used to formulate binder is limited 

by the standard to the maximum level of the resin specification used during the 

performance testing.

§63.1183(e) Maintain the free-formaldehyde content of 

each resin lot and the formaldehyde content of each binder 

formulation at or below the specification ranges established 

during the performance test.
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

Therefore, the limit is not based upon the maximum free-formaldehyde used during the 

performance testing, but is based upon the maximum in the resin specification. The 

agency must concur that the resin shipments used during the performance testing are 

representative of resin specification.

The Phenix City facility uses only one resin under one resin specification. The current 

resin is purchased from Dynea. A copy of the resin specification and Certificates of 

Analysis for resin free formaldehyde can be found in the Appendix, Section E.2.

B.5 Cupola 

B.5.1 Description

A cupola is defined in §63.1196:

Cupola means a large, water-cooled metal vessel to which 

is charged a mixture of fuel, rock and/or slag, and 

additives. As the fuel is burned, the charged mixture is 

heated to a molten state for later processing to form mineral 

wool.

The cupola at the Phenix City facility is heated using a combination of combustion air 

(preheated from the Envirotech incinerator) and coke. A detailed description of the setup 

and operation of the cupola along with the Environmental controls can be found in the 

Appendix, Section E 3.1.

B.5.2 MACT – Carbon Monoxide

In §63.1178(a)(2), the MACT standard places a requirement on control of carbon 

monoxide from new or reconstructed cupolas. Although the Phenix City cupola controls 

CO using an incinerator, it is not regulated under this standard due to the definition of 

“new” or “reconstructed” source. According to the definition found in §63.1196:

New Source means any affected source the construction or 

reconstruction of which is commenced after May 8, 1997.

The cupola within the Phenix City facility was built in 1989 and has not been 

“reconstructed” based on USEPA definitions.

B.5.3 MACT – PM as HAP Surrogate

For all cupolas, the MACT standard identifies particulate matter (PM) as the surrogate 

parameter for metal HAPs. The standard [§63.1178(a)(1)] defines PM by citing the 

USEPA Method 5 test method, commonly referred to as filterable particulate. This plan 

details the procedures followed and the precautions taken to control the rate of particulate 

emissions from the cupola.
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

B.5.4 Cupola w/ Baghouse

B.5.4.1 Overview 

Mineral wool fiber is produced by melting several raw materials in a cupola type melter. 

The rockwool at Phenix City is made from three ores: basalt, dolomite, and limestone. 

These three materials are melted in a cupola type furnace that uses coke as fuel to 

produce a melt that is fiberized to produce mineral wool fiber. No slag is melted within 

this cupola per State permit requirements.

The cupola furnace used to produce the mineral wool material is a vertical shaft type 

melter. It consists of vertical carbon steel cylinder closed at the bottom except for a 

channel from which to extract melt and provided with a sealing door at the top to charge 

raw materials. Melt exits toward the bottom of the cupola and flue gasses exit at the top 

of the cupola. 

Flue gas exiting the cupola consists of gasses generated by the combustion of the coke 

and the calcining of the carbonate containing raw materials. These gases contain 

significant levels of particulate both from entrained fines from the charge and recondensed particulate from the melt. The flue gas cleaning system consists of two major 

units: an inertial separator (designated as the preheater/cooler separator) and a bag type 

pulsejet dust collector. The inertial collector is designed to remove large particulate form 

the stream. Located immediately after the inertial collector, is the bag type dust collector. 

This unit is designed to remove fine particulate from the cupola exhaust. The unit is 

equipped with felted Nomex filtration media (bags), which is covered with a PTFE 

membrane providing fine particulate separation capability. This collector is equipped 

with pulse-jet cleaning which utilizes bursts of compressed air admitted to the clean side 

of the media to remove collected particulate. The cleaning mode of the collector is 

initiated by a high-pressure drop across the unit, the pressure drop being continuously 

monitored and controlled by the process control system. A triboelectric type bag leak 

detector is provided at the collector outlet to indicate high particulate levels indicating a 

bag failure or similar condition. The removed particulate is collected in a hopper located 

below the bags and removed from the system via a screw conveyor and rotary airlock. 

The dust is collected in a portable hopper.

A more detailed description of the cupola and exhaust cleaning system can be found in 

the Appendix, Section E.3.1.

B.5.4.2 Startup and Shutdown of Cupola

The cupola in use at the Phenix City facility is shutdown on a frequent basis (every 5 to 

14 days) in order to recharge the coke bed, replace the siphon, and other maintenance 

items. This unit is incapable of running continuously for periods in excess of 14 days.

During each startup and shutdown episode, procedures will be in place to ensure the 

Envirotech control device is operated in a manner to reduce emissions from the cupola.

B.5.4.3 Malfunctions of Cupolas

Since the cupola at the Phenix City facility is equipped with a control device, there are no 

separate malfunction procedures written. The malfunctions that are deemed critical to 
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

emissions will be described as they pertain to the operation of the baghouse. Cupola 

operational malfunctions that do not interfere with the baghouse will not be dealt with in 

this document.

B.5.5 Baghouses

B.5.5.1 Overview

Baghouses consist of bags made of a filtering material that are installed in parallel. The 

number of bags for an installation is determined by the desired surface area of cloth that 

is needed to treat the air stream at a given pressure drop. PM collected on the cloth 

surface is periodically cleaned by some means – mechanical, sonic, or pneumatic. A dust 

collection system is used to collect and transport the PM released from the bags. 

Bag leak detection systems are devices placed in the air stream after the bags. These 

devices can detect the concentration of PM in the air stream and will alarm when a 

predetermined concentration is exceeded.

B.5.5.2 Malfunction

There are two main categories of malfunctions for a baghouse, those that cause the 

baghouse to be bypassed to protect the baghouse and those that reduce the collection 

effectiveness of the baghouse. Known malfunctions in both these categories are 

discussed in Section D.1.4.3. 

B.5.5.3 Monitoring

Due to the installation of the bag leak detection system, there are no requirements for 

monitoring the operation of the baghouse itself. However, procedures must be in place to 

respond to the bag leak detection system alarm. These are listed in Section D.1.4.4.

B.5.6 Bag Leak Detection System

B.5.6.1 Overview

Bag leak detection systems are devices that are placed in the air stream after the bags. 

These devices can detect the concentration of PM in the air stream and will alarm when a 

predetermined concentration is exceeded. Per 40 CFR 63.1184, the bag leak detection 

system must meet the following requirements:

 Certified by the manufacturer to be able to sense PM concentrations below 10 

milligrams per actual cubic meter (0.0044 grains/scf) (A certification document 

can be found in the Appendix, Section E.3.3.1.)

 Produce an output of relative PM emissions

 Audibly alarm where it can be heard by the appropriate plant personnel when the 

preset level is exceeded

 Proper installation, including consistency with referenced USEPA guidance 

documents

 Initially adjusted
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

 Not subsequently adjusted unless proper procedures are followed

B.5.6.2 Operations & Maintenance

§63.1184(f) requires that triboelectric bag leak detection system be installed, operated, 

adjusted, and maintained in a manner consistent with the USEPA guidance, “Fabric Filter 

Bag Leak Detection Guidance” (EPA-454/R-98-015, September 1997). Other systems 

shall follow manufacturer’s written specifications and recommendations. A copy of this 

EPA guidance document can be found in the Appendix, Section E.3.3.2.

B.5.6.3 Responding to Leak Detector Alarms

In the event of a baghouse leak detector alarm, the standard indicates the proper 

procedures to document the alarm.

§ 63.1192 (b)(2) All bag leak detection system alarms. 

Include the date and time of the alarm, when corrective 

actions were initiated, the cause of the alarm, an 

explanation of the corrective actions taken, and when the 

cause of the alarm was corrected.

The follow examples of corrective actions are given in the regulation for response to the 

bag leak detector alarm and are incorporated into the malfunction plan.

§ 63.1187 (b)(5)(i) Inspecting the fabric filter for air leaks, 

torn or broken bags or filter media, or any other condition 

that may cause an increase in emissions. (ii) Sealing off 

defective bags or filter media. (iii) Replacing defective 

bags or filter media, or otherwise repairing the control 

device. (iv) Sealing off a defective fabric filter 

compartment. (v) Cleaning the bag leak detection system 

probe, or otherwise repairing the bag leak detection system. 

(vi) Shutting down the process producing the particulate 

emissions.

B.5.7 Cupola Melt Rate Monitoring

B.5.7.1 Overview

The production rate of a cupola is known as “melt rate”. In a standard cupola, raw 

materials and fuel (coke) are charged into the device and are heated with combustion air. 

Since flow from the cupola is governed by gravity, the raw materials gradually move 

downward heating as they move. When a certain temperature is reached within the unit, 

the raw materials begin to soften and subsequently liquefy. The liquid material, “melt”, 

is removed from the cupola toward the bottom of the unit and is fiberized using a 

standard rockwool wheel type fiberizing process.

The definition of “melt” and “melt rate” can be found in §63.1196:

Melt means raw materials, excluding coke, that are charged 

into the cupola, heated to a molten state, and discharged to 

the fiber forming and collection process.
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

Melt Rate means the mass of molten material discharged 

from a single cupola over a specified period of time.

B.5.7.2 Melt Rate Measurement

Since there is no automatic method of measuring the rate of molten material coming from 

the cupola, means have been devised to measure the input raw materials on a per 

“charge” basis. Based on the definition of “melt” shown above, and based on the 

requirements of §63.1188(g) for determining melt rate during the performance test, the 

weight of all raw materials added to the cupola was monitored with the exception of 

coke. More details can be found in Section D.1.6.

B.6 Rockwool Curing Oven

B.6.1 Description

The definition of “curing oven” and “incinerator” can be found in §63.1196:

Curing oven means a chamber in which heat is used to 

thermoset a binder on the mineral wool fiber used to make 

bonded products.

Incinerator means an enclosed air pollution control device 

that uses controlled flame combustion to convert 

combustible materials to noncombustible gases. 

The curing oven located within the Phenix City facility uses an incinerator (also referred 

to as a thermal oxidizer) to control VOC emissions. A pictorial representation of the 

oven and corresponding airflows is located in Section E.3.2.1. 

B.6.2 MACT – Formaldehyde as HAP Surrogate

The HAPs of concern for this standard are phenol, methanol, and formaldehyde. 

However, formaldehyde was selected as the surrogate parameter for all of these HAPs. 

B.6.3 Curing Oven Startup & Shutdown

Emissions from the curing oven go to a control device. Prior to the startup of the 

manufacturing line, the oven control device is put on line and checked to assure that it is 

operating within the established limits. 

If the oven control device operation falls outside of the MACT limits, then the 

manufacturing line is shut down. There are no special procedures required for the 

shutdown of the manufacturing line.
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

B.6.4 Oven Incinerator

B.6.4.1 Overview

The curing oven “incinerator” is a system that collects the fumes from the curing oven 

and treats those fumes within a thermal oxidizer. A minimum operating temperature, 

established during the MACT performance testing, is used as an absolute limit. In other 

words, no rockwool insulation product shall be run through the oven until the thermal 

oxidizer firebox temperature is at or above this minimum temperature. 

The standard requires that the incinerator be operated to keep the 3-hour block average of 

the incinerator temperature above the average established during the performance testing 

[§63.1179(b)(2)]. 

IIG MinWool LLC continually monitors the firebox temperature and sets alarms at or 

above the established minimum average temperature. If the firebox temperature falls 

below the minimum temperature, the curing oven is shut down until the problem is 

identified and resolved. Because the reaction procedure is based upon real time 

temperature data, not the three-hour block average, the three-hour block temperature 

should never fall below the minimum level while the curing oven is in operation.

B.6.4.2 Malfunction

Given the above procedure (line shutdown) and the annual inspection, there are no 

malfunctions in the manufacturing line or thermal oxidizer that will cause excess 

formaldehyde emissions. The incinerator portion of the line is coupled closely to the 

curing oven. As long as the curing oven is operating properly and as long as temperature 

is maintained in the incinerator, formaldehyde emissions will remain in check.

B.6.4.3 Annual Inspections

The standard requires an annual inspection of the incinerator system to assure that it is in 

good working order. [§63.1187(b)(3)]. Documentation of the inspection and any 

resulting repairs must be filed as part of the MACT records. 

B.6.5 Oven Incinerator Temperature Monitoring

B.6.5.1 Overview

§63.1192(b)(4) requires the monitoring and recording of the temperature of the thermal 

oxidizer firebox, averaged over a three-hour block. These average block temperatures 

must be above the average temperature established during the performance testing. The 

operating schedule of the manufacturing line will need to be included as part of the 

MACT record for correlation with these three-hour block average temperatures.

B.6.5.2 Malfunctions

Operation of the temperature monitoring system is required for the operation of the 

incinerator. If the temperature monitoring system fails, the curing oven must be shut 

down until the problem is resolved.
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

C Resin Free Formaldehyde Monitoring

The MACT standard requires that the formaldehyde content for each resin shipped to the 

facility be recorded. The Certificate of Analysis (C of A) from the resin vendor, which 

includes the free formaldehyde content, will be checked and the free formaldehyde data 

will be retained for each shipment of resin. 

MACT also requires that no binder be formulated with a resin that contains a level of free 

formaldehyde higher than the upper specification that was used during the performance 

tests. 

C.1 Resin Vendor Certificate of Analysis

The maximum allowed formaldehyde content is 9.0%, based on the resin specification 

Dynea 367-10 (found in Section E.2.1).

During the performance sampling, the average free formaldehyde content, as measured 

by Dynea, was 8.86% which is considered to be at the very top of the specification 

maximum of 9.0%. The C of A’s collected during the performance sampling can be 

found in Section E.2.2.

C.2 Monitoring

Prior to unloading any shipment of resin, the Certificate of Analysis corresponding to that 

shipment will be reviewed by an IIG MinWool LLC employee. The free formaldehyde 

level will be checked against the maximum limit of 9.0% and the C of A will be signed to 

confirm the level has been checked. The signed and dated C of A’s will be kept in the 

Quality Assurance lab. 

C.3 Corrective Actions

If the level of free formaldehyde in any resin shipment (as indicated by the vendor C of 

A) exceeds 9.0%, the shipment of resin will be rejected and will not be unloaded. 

Note that there are no exceptions to this requirement, 

regardless of the potential impact on the facility. 

C.4 Required Records

The following records must be kept per §63.1192(b)(3):

The free-formaldehyde content of each resin lot and the 

binder formulation, including formaldehyde content, of 

each binder batch used in the manufacture of bonded 

products.
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

D Cupola and Curing Oven SSM/OMM

D.1 Cupola

A detailed description of the cupola can be found in Section E.3.1 and a P&ID diagram of 

the operation can be found in Section E.3.1.1. Startup and shutdown checklists can be 

found in the Appendix, Section E.5.1.

D.1.1 Startup and Shutdown Procedures

The cupola in operation at the facility goes through a shutdown and startup cycle 

relatively frequently as discussed elsewhere in this document. The startup sequence can 

be described as follows:

Cupola Startup

 Start Envirotech system

 Charge cupola with 2100 lbs coke before normal charging

 Inject blast air at 3000 scfm when temperature is 850 °F (minimum) and 

incinerator T-1 temperature is 1000 °F (minimum) 

 Light cupola with oxygen lance 

 Add oxygen enrichment to blast air at 7500 cfh

 Send exhaust gases to Envirotech by switching to S-3 mode

 Seal tapping hole when melt flow is obtained

 Increase blast air to 3800 scfm when melt flows from siphon

The cupola in operation at the facility goes through a shutdown and startup cycle 

relatively frequently as discussed elsewhere in this document. The shutdown sequence 

can be described as follows:

Cupola Shutdown

 Prepare deck for cupola drop

 Open tapping hole and drain melt

 Set blast air to 2500 scfm

 Drop cupola contents to pit

 Select Envirotech S-2 mode (auto switch to S-1 stop at timeout)

D.1.2 Required Records

The following records must be kept per §63.1193(b)-(c):

 A completed startup checklist for each startup of the cupola, including any 

deviations from the written procedure contained within this plan.
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

 A completed shutdown checklist for each shutdown of the cupola, including any 

deviations from the written procedure contained within this plan.
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

D.1.3 Baghouse

D.1.3.1 Operations & Monitoring

The Bahnson Norblo baghouse in operation at the Phenix City facility is used to control 

particulate emissions from the cupola. It employs a typical pulse jet cleaning system to 

remove dust from a series of 312 Nomex felt filter bags with PTFE membranes (39 rows 

of 8 bags each). The cleaning cycles are operated via a pressure drop; when the pressure 

across the bags reaches a certain maximum, the cleaning cycle is engaged, a pulse of air 

enters the clean air side of the bag, and the filter cake is removed thus lowering the 

pressure. The current set up for the baghouse is to run at a DP of about 7” w.c. Once this 

pressure is reached the cleaning cycle begins using a short pulse of air throughout the 

entire baghouse, row-by-row.

In order to insure adequate removal of particulate and normal operation of the baghouse, 

a triboelectric leak detection system is used. The bag leak detector is described in 

Section D.1.5. The baghouse is also inspected on at least a monthly basis. Inspections 

are described in Section D.1.4.2.2.

D.1.3.2 Maintenance: Calibration and Inspections

D.1.3.2.1Calibration

The DP Cell transmitter used for the operation of the pulse jet system will be calibrated 

on at least an annual basis, or when a problem is suspected. The maintenance checklist 

for calibrating the DP cell can be found in the Appendix, Section E.5.3.

D.1.3.2.2 Inspections

There will be two frequencies of inspection for the baghouse, monthly and bi-annual. In 

each case as problems are found, they will be documented and fixed as soon as is 

practicable. Note that monthly inspections may be done on a more frequent basis, but 

will be done no less than monthly. The bi-annual inspections will take the place of the 

monthly inspections for those months the inspection is scheduled. Therefore, at a 

minimum there will be 2 bi-annual inspections and 10 monthly inspections per year.

Facility personnel will conduct, at a minimum, a monthly inspection of the baghouse. A 

checklist for the monthly inspection is shown in the Appendix, Section E.5.4.1. The 

elements of this monthly inspection are shown below:

Monthly Inspections

 Inspect clean-air plenum for dust. Clean as necessary.

 Inspect inside of bags for dust accumulation.

 If necessary, do Visolite® leak check determination.

 Inspect all seals around doors.
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

 Inspect diverter plate for holes or other damage. Repair as necessary.

 Inspect all air connections to pulse-jet venturi’s.

 Inspect all air filters on combustion air fans for integrity and cleanliness.

 Inspect and clean baghouse leak detector probe.

The Phenix City Plant will enter into a voluntary contract with BHA group to have a 

semi-annual baghouse inspection completed. The proposal from BHA is located in the 

Appendix, Section E.5.4.2. The elements of this semi-annual inspection are shown 

below:

Semi-annual Inspections

 Lock and tag out main control panel and perform safety orientation prior to 

commencing internal work.

 Vacuum or sweep minor tubesheet accumulation under 2" into the hopper to 

ensure proper inspection for leaks and to facilitate proper bag installation.

 Perform Visolite® Leak Detection test or otherwise visually inspect for leaks 

immediately upon completion of the scope of work to ensure a leak free system.

 Inspect bags visually to determine any problems and evaluate overall condition.

 Change up to 5% of the bags as needed. Bags to be provided by customer.

 Inspect for and repair minor leaks in tubesheet and housing.

 Inspect for hopper problems such as buildup or bridging.

 Inspect for baffle plate wear.

 Inspect for and repair minor door seal leaks 10% with materials supplied by 

customer.

 Clean static pressure taps for Magnehelic® Gauges or manometers.

 Observe and document cleaning cycle information (frequency, duration, etc.) 

while collector is on-line.

 Observe and record differential pressure readings on each compartment (or as 

appropriate) while collector is on-line.

 Submit a written report on each collector inspected, identifying current condition, 

work completed, inventory use and recommendations.

 Inspect all pulse valves and solenoids for proper operation and repair up to 20% 

with repair parts supplied by customer.

 Inspect cages for corrosion and overall condition.
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D.1.3.2.3Envirotech System Maintenance

The Envirotech unit controls emissions from the cupola and consists of a baghouse and 

incinerator (for CO emissions). A description of this device and the role it plays can be 

found in Section E.3.1.

The documented maintenance schedule for this device can be found in the Appendix, 

Section E.5.5.

D.1.3.2.4 Spare Parts List

As part of the ongoing operation of the baghouse, the Phenix City facility will have the 

following spare parts, at a minimum, on-hand:

 15 Bags (Nomex felt bags w/ PTFE membrane)

 10 Cages

 10 Sets of air cleaning solenoids and diaphragms

 1 Spare screw for baghouse dust conveying system

D.1.3.3 Operational Malfunctions

D.1.3.3.1Baghouse Inlet High Temperature Alarm

The flue gas from the cupola is cooled via a heat exchanger, as described in Section 

E.3.1, prior to entering the baghouse. The Nomex bags currently in use cannot be used 

for extended periods above 450oF. In the event the temperature in the inlet to the 

baghouse reaches a critical point, the baghouse will be bypassed to prevent destruction of 

the Nomex filter media. In some instances, the bypass lasts for only several minutes until 

the temperature can be lowered. If the temperature cannot be reset within 30 minutes, a 

malfunction condition exists and the following steps will be taken to correct the situation:

 Insure cooling to the heat exchanger is maximized.

 Continue to bypass the baghouse to prevent damage to the filter media if 

temperature reaches critical level.

 Monitor and respond to cupola as necessary to reduce temperature.

 If none of the above steps correct the temperature problem within 1 hour of 

bypassing the baghouse, the agency must be contacted per the facilities State 

Operating Permit.

A checklist can be found in Section E.5.4.3.

D.1.3.3.2 Other Bypass Events

There are other malfunctions that can lead to a bypass of the baghouse. These 

malfunctions will be detected via monitoring of the process. As part of troubleshooting 

any bypass, standard procedures will insure malfunctions that hamper baghouse 

performance are examined. In all instances, the bypass will be concluded as soon as is 

practicable to insure safety of employees and to prevent damage to equipment. 

The main response to a bypass without an immediate alarm or known cause is to:
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 Insure the stack cap is open for a reason (such as a power failure), and 

troubleshoot problem. If not, or if system has been accidentally tripped, close 

stack cap.

 If bypass has occurred because of an assignable cause, document time and date of 

occurrence, cause, and steps taken to fix problem.

A checklist for a bypass event caused by unplanned issues, such as power outages, 

general equipment failure, operator error, and the like, can be found in the Appendix, 

Section E.5.4.5.

D.1.3.4 Responding to Leak Detector Alarm

The leak detector alarm has been calibrated by B3 Systems in accordance with 

recommendations cited within the EPA Baghouse Leak Detector Guidance document. 

Although ideally a calibrated leak detector will alarm only when there is a leak, there has 

been evidence that the leak detector in place within the facility can alarm for several 

minutes at a time during cleaning cycles. In these instances, Visolite® leak checks have 

shown no noticeable bag leaks. For this reason, it becomes necessary to define an alarm 

as “a continuous alarm that lasts for a minimum of 15 minutes”.

In the event of a continuous alarm, the following procedure will be done:

 The time and date will be documented.

 The most recent 24-hour detector trend will be examined to determine if the alarm 

has resulted from a “sudden” jump or a longer-term rise.

 All systems will be examined to insure there has not been a cupola upset that may 

be causing problems with the baghouse.

 As soon as is practicable, B3 Systems will be contacted to run a diagnostics on the 

probe to determine if the system is operating properly.

 As soon as is practicable, the leak detector probe will be removed and will be 

cleaned in accordance with manufacturer’s recommended practices.

If none of these steps solve the problem, and the baghouse remains in alarm, the 

following steps will be followed:

 If there has been a known problem (over temperature of the baghouse for 

example) where a catastrophic failure of the system is possible, shut the cupola 

down as soon as is practicable.

 If there has been no known problems with cupola operation, continue running the 

cupola until the next scheduled downtime, but no later than 120 hours from the 

initial alarm. Do not bypass the baghouse.

The current inlet loading on the baghouse is >150#/hour. Bypassing the baghouse for 

even a short amount of time while in a leak detector alarm mode would be allowing an 

inordinate amount of emissions into the atmosphere. Even with multiple broken bags, the 

level of dust escaping from the system has been shown to be minimal (<5#/hour).
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In order to “take the cupola down”, numerous items have to be in place. A standard 

downtime lasts for at least 12 hours and takes a large number of Plant personnel to 

accomplish in a safe manner. Waiting at most

Once the cupola is down and it is safe to enter the baghouse, the following steps will be 

taken to determine the reason for the leak detector alarm:

120 hours from the onset of a leak detector 

alarm to shut the system down would be consistent with safe operating practices. Once 

the cupola is down, other safety factors have to be considered such as CO levels in the 

system.

 Visually inspect the clean air plenum in the baghouse.

 Visually inspect the insides of all bags.

 Inspect the diverter plate near the inlet of the baghouse.

 Visually inspect the outside of the first several rows of bags.

 Correct any problems found including sealing off or replacing the bag or bags.

 When completed, run a Visolite® leak check on the system to insure all potential 

leaks have been repaired.

 Once all bags have been shown to be intact, go through the standard monthly 

inspection list.

A checklist to follow can be found in the Appendix, Section E.5.4.4.

D.1.4 Bag Leak Detection System

D.1.4.1 Monitoring

The calibration and setup of the baghouse leak detection system will be completed 

through contractual arrangement with B3 Systems. The Phenix City Plant will monitor 

the output of the leak detector. If the leak detector signal results in an audible alarm, 

facility personnel will respond as described in Section D.1.3.4.

D.1.4.2 Maintenance & Calibration

Maintenance will be performed on the leak detector probe on a monthly basis as 

described in D.1.3.2.2.

IIG MinWool LLC has entered into a contractual arrangement with B3 Systems to 

monitor and calibrate the baghouse leak detection system. B3 follows recommendations 

found within the Leak Detector Guidance document found in the Appendix, Section 

E.3.3.2. Responsibility of daily monitoring, probe cleaning, and response to audible 

alarms is that of IIG MinWool LLC.

EPA’s “OAQPS Fabric Filter Bag Leak Detection Guidance” provides information on 

how to initially setup the baghouse monitors and how to conduct on-going quality 

assurance procedures. The guidance is somewhat subjective and allows for differing 

procedures based on facility-specific issues. The yearly monitor setup procedures and 

results must be documented and certified by the personnel who conduct them. B3 

Systems has developed a procedure whereby they can access the baghouse leak detector 
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

and conduct the monitor setup procedures remotely. In this procedure, they adjust the 

sensitivity, zero offset, span multiplier, time constant, alarm level, and alarm delay for 

each sensor.
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D.1.5 Cupola Melt Rate Monitoring

D.1.5.1 Operation

The device in use measures the weight of all raw materials, “the charge”, entering the 

cupola. The system is referred to as the “ABB Advant with Operate IT”. Raw material 

weights are continuously added for each “charge” over a period of 12 hours (once per 

shift) at which time the counters are reset. To determine the total amount of any or all 

raw materials, one simply subtracts the reading at the end of the period in question from 

the reading at the beginning of the period in question.

The various rock types that make up the recipe for a “charge” are stored in bins in the 

rockhouse. Each bin holds one particular type of rock. However, two separate bins may 

hold one type of rock. The “charge” is made up of X pounds of each type of rock. The 

“charge” is called for through an “on demand” system from the Cupola. The control 

system then energizes the appropriate bins, constantly registering the weight change until 

the recipe is satisfied. As the rocks are fed from the bins, a conveyor system then travels 

the rock to the top of the Cupola. This process is repeated on a cycle of approximately 

10-12 minutes.

D.1.5.2 Monitoring Requirements

The current system in use to monitor raw material input in to the cupola is described in 

section D.1.6.1. The raw material input will be determined on a per shift block basis 

(shifts vary between 8 and 12 hours) and will be converted to throughput in pounds per 

hour. The method is outlined below:

Throughput (#/hr) = 

Shift time (8 or 12 hours)

(total basalt + total dolomite + total limestone) pounds

Based on the requirements of the standard, coke does not get included as input raw 

material into this equation. The value will be recorded in the operators logbook every 8 -

12 hours when the unit is operational.

D.1.5.3 Calibration Program

The ABB System must be calibrated in accordance with manufacturer’s 

recommendations at a minimum. Calibration will be conducted, at a minimum, on a biannual basis. The Phenix City facility will calibrate these scales by performing the 

following tasks. 

The scale calibration consists of placing known weights on the scale platform that equals 

10% of the scales’ capacity. The scale then is placed into calibration mode, the variables 

are keyed into the unit, and it runs a self-calibration routine. A known weight is then 

reapplied to the scale platform to verify the weight being displayed. After this, the signal 

from the scale to the control system is calibrated.
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D.1.5.4 Malfunctions

In the event the ABB System malfunctions, the following will be done to insure timely 

resolution.

If a scale malfunction occurs, the system is changed to a bin that a particular rock type is 

charged from. This allows facility personnel to repair the scale or feeder without any 

effect to the process. If the problem is related to a bin for which this is not possible, 

charging must be stopped and the cupola must go into a “bank” mode. This mode allows 

Operations to hold the molten rock in the Cupola until the repairs are completed.

Malfunctions can include scale failures, signal feedback problems, vibrating feeder 

failures or conveyor belt problems. Since many of these malfunctions cannot be fixed 

short of device replacement, the facility will keep a number of items within the spare 

parts inventory, and simply replace them as needed. Note that if a device fails that 

prevents the ABB System from working, charging of raw materials to the cupola halts as 

does production.

D.1.6 Spare Parts List

Because of the type of malfunctions that occur, the facility will keep the following spare 

parts in inventory:

 scale controller

 load cell

 vibrator coil and core

 S.C.R. for the vibrator controller

 pneumatic vibrator
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D.2 Curing Oven and Incinerator

D.2.1 Startup and Shutdown Procedures

The startup and shutdown procedures for the curing oven are shown below. It is 

imperative to insure that the incinerator temperature is at or above setpoint whenever 

product is introduced into the oven. Checklists for the startup and shutdown can be found 

in Section E.5.2.

 Start Filterhouse 3 motor group

Curing Oven Startup

 Start oven chain drive (curing warm mode, 10 f/min)

 Start Integral motor group (includes burner start sequence)

 Allow oven return temperature to reach operational range

 Insure incinerator temperature is at or above 1300oF.

 Begin production

 Empty oven

Curing Oven Shutdown

 Incinerator temperature can be lowered below 1300oF at this stage

 Shut off oven burners

 Allow oven return temperature to fall to 200 degrees

 Shut off chain drives

 Shut off Integral motor group

 Shut off Filterhouse 3 if rollup is not running

D.2.2 Maintenance

The oven and incinerator are closely coupled devices. Maintenance of these two systems 

is integral to the proper operation of the control device. Maintenance task checklists can 

be found in the Appendix, Section E.5.6.

D.2.3 Incinerator

D.2.3.1 Annual Incinerator Inspection

The annual inspection covers both the internal and external portions of the oxidizers. For 

the internal evaluations, the oxidizer must be shut down in advance to cool down to 

ambient temperature for personnel entry. 
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The SAP description of both the internal and external phases of the annual evaluation that 

will be performed can be found in Section E.4.1. The most recent incinerator inspection 

report can be found in the Appendix, Section E.4.2.

D.2.3.2 Malfunctions

D.2.3.2.1Exhaust Fan Malfunction

If the exhaust fan malfunctions, the operator will take the following actions:

 Stop all product on the line.

 Shut off all oven burners.

 Shut off all incinerator burners.

 Call maintenance if fan cannot be restarted.

A checklist for the exhaust fan failure can be found in the Appendix, Section E.5.7.2.

D.2.4 Incinerator Temperature Monitoring

D.2.4.1 Monitoring Parameter Deviation

During performance testing a minimum temperature was determined for the curing oven 

incinerator. The detailed information can be found in the final compliance report, 

Section E.6.3.

Minimum Temperature: 1292oF

The following procedure will be followed:

During normal operation, the incinerator will be continuously monitored for temperature. 

In the event that the incinerator temperature drops below the minimum determined during 

compliance sampling, an alarm will sound and the operator will respond within one hour 

if product is running through the oven. Reaction procedures include:

 Insure set point has not drifted, adjust as necessary.

 Insure all fans and burners are operating properly.

 Call electrician to determine if thermocouple is responding properly.

 If above steps do not fix device, stop production until problem can be resolved.

On an ongoing basis, the facility will maintain records of the incinerator temperature in 

two formats. On a weekly basis, a trendchart will be printed showing the continuous data 

stream. Also, records will be kept in an hourly average format – 24 datapoints per day. 

A checklist for a low temperature deviation has been added to the Appendix, Section 

E.5.7.3.

D.2.4.2 Maintenance and Calibration

The incinerator thermocouple will be changed out as needed or once every six months at 

a minimum in conjunction with calibration of the transmitter. The procedure for 

calibration of the transmitter can be found in the Appendix, Section E.5.7.1.
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D.3 Binder Formulation Monitoring

D.3.1 Binder Formulation

The binder used in the Mineral Wool Manufacturing process is a standard urea-extended, 

phenol formaldehyde based binder. A list of the ingredients and purpose is shown below:

Phenolic Resin (Dynea 367.10): main bonding agent

Urea: extender (reacts with formaldehyde to form UF resin)

Ammonia: stabilizing agent used to keep pH elevated

Oil Emulsion: dust suppression agent

Silane: adhesion promoter

Silicone: lubricant / water repellant agent

There is only one binder “formulation” in use at the facility for cured board products. 

The identification of this binder is simply Line Binder. It is important to note that the 

level of some ingredients is dictated by the solids level desired and by the actual % solids 

of the incoming raw materials. The following chart shows a typical batch formulation for 

board products. Also shown in the chart are the levels of ingredients used during the 

performance testing (note that a 40% batch size was used during sampling).

Ingredient Typical 

Pounds 

in a 

Batch

% Solids of 

Ingredient

Total % 

of Batch 

Mix

Pounds of 

Solid in 

Batch

Pounds 

Used 

During 

Testing

Resin 4644 50% 20% 2322 1814

Urea 4954 20% 21% 990.8 1936

Water 12000 0% 51% 0 4775

Ammonia 480 0% 2% 0 200

Silane 16 1% 0% 0.16 5.77

Silicone 8 60% 0% 4.8 4.54

Mulrex 500 45% 5% 540 250

Total 22602 100% 3857.76 8985

The key components of the binder that we believe impact formaldehyde emissions from 

the curing oven are resin and urea content and resin type. The other components of the 
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

formulation do not play a significant role in formaldehyde emissions. The Phenix City 

facility makes a master batch of “premix” which is a mixture of resin and urea. This 

master batch is used to feed all binder formulations each day.

It is the opinion of IIG MinWool LLC that as long as the relative ratio of urea to resin 

stays the same, the resin free formaldehyde content stays below the performance 

specification, and the same resin (Dynea or equivalent) are used, the level of 

formaldehyde emissions from the curing oven will be within the MACT compliances 

limits.

Changes in these levels beyond that which was used during compliance testing must 

be followed by performance sampling.

Changes in binder ingredients, manufacturer, or levels of impurities must be 

scrutinized by responsible Environmental personnel.

D.3.2 Monitoring

The facility will keep a running record of premix formulations. Typically, one premix is 

made per day. This premix is used in all Line Binder formulations.

Based on data supplied during MACT compliance sampling, the ratio of resin to urea can 

be determined as follows:

pounds resin used / pounds urea used = resin:urea ratio

2322 lbs solid resin / 990.8 lbs solid urea = 2.34 : 1 ratio

If we assume a good number for each weight is +/- 2%, then we have a maximum range 

of resin to urea as:

2368 lbs solid resin / 971 lbs solid urea = 2.44 : 1 ratio (or +4%)

Since addition of urea to the binder does not constitute a change in “binder formulation”, 

there is no minimum value, i.e., more urea can be added without requiring a response.

Monitoring Range => less than or equal to 2.44:1 resin to urea

D.3.3 Monitoring Parameter Deviation

If the monitoring parameter is higher than 2.44, the operator will add enough urea to 

reduce the ratio to between 2.25 and 2.44.

If the ratio of resin to urea is higher than 2.44 and the pre-mix is used to make binder, the 

operator must make note of the deviation. All attempts must be made to insure the 

premix falls inside the monitoring parameter.
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E Appendices
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

E.1 Regulations

E.1.1 General Provisions 40CFR63 Subpart A

E.1.2 MACT – Mineral Wool Production – 40CFR63 Subpart DDD
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E.2 Resin Free Formaldehyde

E.2.1 Resin Specification – Dynea 367.10

E.2.2 Resin Certificate of Analysis

<Attach copies of the C of A’s generated for resin used during performance tests.>
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

E.3 Equipment Documents

E.3.1 Cupola – General Description

1.1. General: Mineral wool fiber is produced by melting several raw materials in a 

cupola type melter. At the Phenix City plant , rockwool is produced as opposed 

to slagwool which refers to the raw material source. Mined raw minerals are used 

to produce rockwool while blast furnace slag is used to produce slagwool. The 

rockwool at Phenix City is made from three ores: basalt, dolomite, and limestone. 

These three materials are melted in a cupola type furnace that uses coke as it’s 

fuel to produce a melt which is fiberized to produce mineral wool fiber.

1.2. Cupola Melter: The cupola furnace used to produce the mineral wool material is 

a vertical shaft type melter. It consists of vertical carbon steel cylinder closed at 

the bottom except for a channel from which to extract melt and provided with a 

sealing door at the top to charge raw materials. Combustion air for the solid coke 

fuel is injected at the bottom while the flue gases are exhausted at the top of the 

melter. Materials charged to this style of melter are large in size, being several 

inches in diameter, to create a porous bed within the melter. This porous bed 

allows for the flow of hot combustion gases up through the furnace for melting 

and preheating of the charge while at the same time allowing melt to flow down 

through the melter to supply the process. The cupola melter is water jacketed in 

the high temperature areas of the melter to protect the carbon steel shell from 

thermal damage. In lower temperature areas such as the charge end it is 

refractory lined. The cupola further can be described as a series of zones running 

from top to bottom of the furnace. These zones are designated as follows: the raw 

material charge zone, the raw material preheat zone, the melt zone, the 

combustion zone and the coke bed or well zone. These zones are described in 

detail below.

1.2.1. Raw material charge zone: Raw materials, which are stored in remote 

silos, are charged to the top of the furnace along with the coke used as the 

fuel source. The raw materials are metered simultaneously using vibratory 

feeders equipped with load cells unto a belt charge conveyor that takes the 

charge to the top of the cupola furnace. The material is fed into a pre-charge 

chamber located at the top of the furnace. A rotary distribution device 

distributes the charge across the cross-section of the melter on entry into the 

pre-charge chamber. The coke is charged in a similar manner and precedes 

the main charge as it is loaded into the cupola melter. In this way, the 

vertical shaft of the furnace is filled with alternating charges of raw material 

and coke. Material is transferred from the pre-charge area of the cupola to 

the main melting chamber on demand, based on the raw material level in the 

cupola. Raw material from the charge zone enters the preheat zone as raw 

material is consumed in the melter. 

1.2.2. Preheat zone: Here raw materials are preheated to their melting points by 

hot combustion gases from the combustion zone as they are drawn up 
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through the melter and vented out of the furnace to the flue gas handling 

system. In addition to preheating raw materials carbonate compounds 

contained in the dolomite and limestone are calcined to alkaline oxides 

thereby releasing significant amounts of CO2 in this zone.

1.2.3. Melting zone: Here the raw materials are converted to liquid both 

thermally and through chemical action. Temperatures in this zone can reach 

3500 deg F. The melt rate is controlled both by the available thermal energy 

(rate at which the coke is combusted) and the volumetric through-put 

capability of the furnace.

1.2.4. Combustion zone: At this location, coke, which is charged with the raw 

material, is reacted with preheated combustion air to generate the heat 

release required for melting. The preheated combustion air (900-1100 deg F) 

or blast air as it is referred to enters the cupola at the base of this zone 

through a series of pipes called tuyeres which are evenly spaced around the 

perimeter of the cupola. Some of the tuyeres are also provided with pure 

oxygen, high-pressure lances that are used to enrich the combustion air and 

used to help penetrate the coke bed to provide combustion at the cupola 

center. Coke consumed in the combustion is replenished by successive 

charges moving down the shaft of the cupola. The rate of combustion is 

controlled by the supply of oxygen, which in turn depends on the blast air 

and the lance oxygen rates. As preheated coke enters the combustion zone it 

reacts with carbon dioxide (CO2) from the combustion to form carbon 

monoxide (CO). This reaction is endothermic and removes heat from the 

melter. In addition water vapor entering with the combustion air is also 

reduced to hydrogen and CO. As a result depending on the efficiency of the 

combustion a significant amount of CO can exit the cupola with the flue 

gases. Melt from the melting zone flows down trough the combustion zone 

and is further heated.

1.2.5. Coke bed or well zone: This zone consists of un-burnt coke, which serves 

as a heat resistant porous bed which both supports, the burden of the raw 

material charge above while simultaneously allowing the melt to pass 

through the bed voids and accumulate for supplying the process. Located in 

this zone is the melt siphon which is a melt filled channel extending from 

just above the base of the cupola to just below the tuyeres that supplies the 

process with melt. Melt filling this zone is pressurized by the blast air and 

forced up into the siphon. In this way the siphon channel acts as a liquid seal 

for the blast air entering the melter (it is forced to flow up through the 

cupola). As melt level continues to build in the cupola bottom, hydrostatic 

forces allow the melt to overflow the outlet of the siphon supplying melt to 

the process. Note the coke bed does not combust for the blast air enters 

above this zone and flows up towards the flue gas outlet. Therefore the coke 

bed is contained in non-oxidizing environment and remains intact. In 

addition to the above, this zone also acts as a reservoir to hold molten iron 

formed from the reduction of the iron oxide containing raw materials. This 

iron accumulates below the mineral wool melt due to their specific gravity 
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

differences. The iron is periodically drawn from the cupola to prevent 

plugging of the siphon and to permit continued flow of mineral wool melt. 

The iron is extracted by creating a drain hole through a small refractory 

filled area in the cupola bottom. This accomplished through use of an 

oxygen/magnesium lance that burns through the refractory creating the drain 

hole. After the iron is drained from the unit (the color of the stream 

indicating when it is emptied) the hole is resealed with a refractory patch. 

This operation is referred to as ”tapping the cupola “ and occurs 

approximately every 4 hours of normal operation.

1.3. Flue gas Treatment System: Flue gas existing the cupola consists of gases 

generated by the combustion of the coke and the calcining of the carbonate 

containing raw materials. These gases contain significant levels of particulate 

both from entrained fines from the charge and re-condensed particulate from the 

melt. Principal gaseous contaminants to this stream are hydrogen sulfide, other 

sulfide compounds and carbon monoxide produced by the combustion of the 

coke. To treat this exhaust stream, the gases are filtered then oxidized in a 

thermal oxidizer. The gases are drawn from the cupola by an induced draft fan 

located after the filtration equipment and prior to the oxidizer. Waste heat from 

the oxidizer is passed through a heat exchanger (recuperator) were it heats both 

the blast air used for combustion in the cupola and preheats the filtered flue gas 

from the cupola prior to combustion in the thermal oxidizer. The treated gases 

are existed to a common tall stack with other process treated exhausts from fiber 

forming operations. The flue gas system is described in more detail below.

1.3.1 Flue gas Filtration: This system consists of two major units an inertial 

separator (designated as the preheater/cooler separator) and bag type pulsejet 

dust collector. The inertial collector is designed to remove large particulate form 

the stream. The gas is routed through two sets of parallel tube banks and as a 

result of sudden directional changes particulate is removed from the gas stream. 

This separated particulate is collected in a hopper, which is integral to the 

separator, and removed from the system via a screw conveyor and rotary airlock. 

The removed particulate is collected in portable hoppers. This pre-separator 

serves a secondary purpose as it is also used to condition the exhaust gases to the 

proper temperature for handling throughout the remainder of the filtration 

equipment. This unit is constructed similar to a shell and tube heat exchanger 

with raw gases flowing through the interior of two sets of tube banks. Either hot 

exhaust gases from the oxidizer or cool ambient air are circulated on the outside 

of the tubes (shell-side) to either heat or cool the cupola exhaust to approximately 

350 deg F to make it suitable for supply to the dust collector. If too hot gases 

could destroy the filtration media in the dust collector while if too cool the gases 

could condense causing both operational and maintenance problems in the 

collector. Located immediately after the inertial collector, is the bag type dust 

collector. This unit is designed to remove fine particulate from the cupola 

exhaust. The collector consists of a series long small diameter bags suspended 

from a tube-sheet and housed within a metal enclosure. The contaminated air 

enters the enclosure and flows from the bag exterior to the interior leaving the 

separated particulate on the bag exterior in the form of a dust cake. The cleaned 
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

air is combined together in a common plenum above the bag tube sheet and exits 

the unit. The unit is equipped with felted Nomex filtration media (bags), which is 

covered with a PTFE membrane providing fine particulate separation capability. 

This collector is equipped with pulse-jet cleaning which utilizes burst of 

compressed air admitted to the clean side of the media to remove collected 

particulate. The cleaning mode of the collector is initiated by a high-pressure 

drop across the unit, the pressure drop being continuously monitored and 

controlled by the process control system. A triboelectric type bag leak detector is 

provided at the collector outlet to indicate high particulate levels indicating a bag 

failure or similar condition. The removed particulate is collected in a hopper 

located below the bags and removed from the system via a screw conveyor and 

rotary airlock. The dust is collected in a portable hopper.

1.3.2 Thermal Oxidizer/ Recuperator: The thermal oxidizer consists of a 

refractory lined gas fired chamber. Filtered exhaust from the cupola is thermally 

oxidized in this unit. Prior to entering the oxidizer, the gases are passed through 

the recuperator located at the oxidizer outlet, which preheats the gases. The 

preheated gases are then fed to the oxidizer and mixed with combustion air as it 

enters the unit. The oxidizer is supplied with a natural gas burner. This burner 

modulates to control temperature within the unit to insure the cupola exhaust is 

adequately oxidized. Much of the heat generated in the unit is from the 

combustion of the carbon monoxide generated at the cupola. This energy is 

recovered in the recuperator by exchanging heat from the oxidizer exhaust with 

the ambient air supplied as blast air and the filtered cupola exhaust gases. 

Cooling air is injected between the oxidizer and the recuperator to cool the 

oxidizer exhaust slightly to help limit blast air temperature going to the cupola. 
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

E.3.1.1 Cupola and Envirotech P&ID

<Insert copy of P&ID Generated by Ron Cseh.>
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

E.3.2 Curing Oven – General Description

Mineral Wool Curing Oven: The curing oven is a rectangular unit 80ft long unit that 

handles 8ft wide material. A continuous stream of mineral wool fiber coated with 

uncured phenolic resin is conveyed into the oven inlet. The function of the oven is 

to cure the phenolic resin and thereby set the fibers to form a rigid fiber pack. The 

mineral fiber pack is approximately 8ft wide and up to 24 inches in thickness as it 

enters the oven depending on the dimensions and density of the finished product. 

The fiber material is captured between two horizontal conveyors with perforated 

flights to allow flow through the pack. These conveyors serve to both transport 

the material through the oven and provide a smooth surface to both sides of the 

product through compression of the fiber pack. The heat source for the oven is a 

gas fueled hot air system. Hot air is primarily supplied to the bottom of the oven 

and forced up through the fiber pack and withdrawn from the top of the unit 

where it is ducted back to the heat source. The hot air supply stream is distributed 

over the entire length of the oven. The heated air supplied to the oven is generated 

in an external gas fired heater, which is used to circulate air as described above. 

The discharge temperature of the air from the heater (oven inlet temperature) is 

used to control the firing rate of the external heater. The discharge air from the 

oven is collected in a common air plenum and routed back to the heater via a 

three-way damper equipped with a proportional type actuator. This damper is 

used to divert a portion of the return air to the gas-fired incinerator. The amount 

of exhaust gas diverted to the incinerator is controlled via the damper position, 

which in turn, is controlled by the pressure in the return air plenum. This 

incinerator is a gas-fired heater used to destroy VOC’s, which are discharged to 

the atmosphere via this oven effluent stream. The incinerator temperature is 

controlled via a thermocouple mounted in the unit, which is used to control the 

gas firing to the unit. A portion of the incinerator discharge is routed back to the 

oven inlet and distributed across the top of the product as a waste heat source. The 

reminder of the treated gases from the incinerator are combined with gases from a 

collection hood at the oven discharge and transported through the No.3 filter 

house and discharged to the 2nd tall stack. The No.3 filter house is a large 

replaceable media filter through which the gases pass to remove any large 

suspended particulate prior to being discharged to the stack.
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

E.3.2.1 Curing Oven Diagram

<Insert diagram of curing oven developed by Frank Kristie.>
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

E.3.3 Baghouse Leak Detector

E.3.3.1 Manufacturer Certification

<Insert letter from ThermoAnderson on Capabilities of PCME probe.>

E.3.3.2 USEPA Guidance on Baghouse Leak Detectors

<Insert document from EPA on Leak Detector Guidance.>
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

E.4 Incinerator Inspections

E.4.1 Annual Incinerator Inspection SAP Document

E.4.2 Most Recent Report

<Insert copy of most recent Reliable Incinerator Inspection.>
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

E.5 Required Checklists

E.5.1 Cupola Startup/Shutdown Checklists

E.5.2 Oven Startup/Shutdown Checklist

E.5.3 Pressure Transmitter Calibration Checklist

E.5.4 Baghouse Checklists

E.5.4.1 Monthly Inspection Checklist

E.5.4.2 BHA Bi-Annual Inspection Proposal / Checklist

E.5.4.3 Baghouse High Temperature Alarm

E.5.4.4 Leak Detector Alarm Checklist
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

E.5.4.5 General Baghouse Bypass Checklist

E.5.5 Cupola Flue Gas Treatment Maintenance Checklists

E.5.6 Curing Oven System Maintenance Checklists

E.5.7 Incinerator Checklists

E.5.7.1 Incinerator Temperature Calibration Procedure

E.5.7.2 Incinerator Exhaust Fan Failure Checklist

E.5.7.3 Incinerator Low Temperature Alarm

E.5.8 Malfunction Procedures not Listed: Form
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

E.6 Historic Documents

E.6.1 Notifications

MACT Protocol Notification: Initial notification of intent to test to ADEM and the 

USEPA.

Test Method Letter ADEM: Initial notification of request for alternate sampling method 

(substituting Method 316 – Wet Method for Method 318 – FTIR).

Phenix City MACT2 – notification to ADEM: Notification to ADEM that time has 

lapsed for a decision based on 45 day requirement in recently finalized General 

Provisions.

E.6.2 Test Protocol

<Unable to insert Adobe Document in this Word File. Final Notebook will contain the 

protocol.>

E.6.3 Final Compliance Report

<Insert Copy of final compliance report into Notebook.>
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

E.7 Applicable Requirements: Summary
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

E.8 Version Control Section

Version Date Sections Changed

1.0 June 2, 2002 Initial Document

2.0 June 10, 2002 Not Captured ...

3.0 June 13, 2002 Added E.7 Version Control

Modified D.1.5, D.1.5.1, D.1.5.2

Added Section B.3 – Malfunctions not Listed in Plan

Added Section E.5.8 – Checklist for Malfunctions no listed 

in plan.

4.0 Aug 19, 2002 Modified Sections E.5.5 and E.5.6 – Removed existing 

maintenance checklists and replaced with streamlined 

versions.

Modified Sections D.1.1 and D.1.2 – simplify startup and 

shutdown verbiage in document to better reflect checklists.

Combined Sections D.1.1 and D.1.2 into D.1.1. Renamed 

D.1.1. (Done to be consistent with oven startup and 

shutdown section.)

Modified Section D.2.4.1 – added statement to describe 

records being kept for incinerator temp monitoring.

Modified Section D.1.4.2.4 – changed number of bags to be 

kept in inventory from 10 to 15 to match BHA inspection.

Corrected Section D.1.4.1 and D.1.4.2 – references to 

D.1.4.4 and D.1.4.2.2 were corrected to D.1.3.4 and 

D.1.3.2.2.

Inserted New Section to Appendix – E.7 Applicable 

Requirements: Summary / Moved existing E.7 to E.8

Added Section D.2.3.2 and D.2.3.2.1 – Exhaust Fan 

Malfunction for Incinerator.

Added checklist to Section E.5.7.2 – Exhaust Fan Failure. 

Changed previous E.5.7 section to E.5.7.1.

Added checklist to Section E.5.7.3 – Low Incinerator 

Temperature.

Modified verbiage in Section A.

Modified section D.3.2 and added Section D3.3 – Better 

statement of monitoring and response requirements for 
Mineral Wool MACT SSM/OMM Plan Version 5 June 12, 2003 

binder formulation.

Modified section D.1.3.4 – defined leak detector alarm.

Added E.5.4.5 – General Baghouse Bypass checklist.

Changed B.6.4.2.1 to B.6.4.3 for consistency.

Added header to each checklist to match the Plan Version 

and date.

5.0 June 12, 2003 Changed all reference to Owens Corning to IIG MinWool 

LLC. Plant and all assets purchased by IIG MinWool LLC 

on May 9, 2003.